Method for producing at least one laser chip, and laser chip

Abstract

A method for producing at least one laser chip is specified, the method including the steps of growing a semiconductor layer sequence having an active zone on a substrate, removing part of the substrate, part of the active zone and part of the semiconductor layer sequence by dry-chemical etching, thereby forming at least one side edge extending, at least in places, transversely or perpendicularly to the main plane of extent of the substrate, and removing part of the substrate, part of the active zone and part of the semiconductor layer sequence at the side edge by wet-chemical etching, the active zone being designed to emit laser radiation. A laser chip is additionally specified.

1 . A method for producing at least one laser chip, the method comprising:
 growing a semiconductor layer sequence having an active zone on a substrate,   removing a part of the substrate, a part of the active zone and a part of the semiconductor layer sequence by dry-chemical etching, thereby forming at least one side edge which extends, at least in places, transverse or perpendicular to the main extension plane of the substrate, and   removing a part of the substrate, a part of the active zone and a part of the semiconductor layer sequence at the side edge by wet-chemical etching, wherein   the active zone is designed to emit laser radiation, wherein   the dry-chemical etching comprises a plasma etching process, and the dry-chemical etching comprises a further plasma etching process different from the plasma etching process.   
     
     
         2 . The method for producing at least one laser chip according to  claim 1 , wherein wet-chemical etching is carried out after dry-chemical etching. 
     
     
         3 . The method for producing at least one laser chip according to  claim 1 , wherein the semiconductor layer sequence is grown by metal-organic chemical vapor deposition. 
     
     
         4 . The method for producing at least one laser chip according to  claim 1 , wherein the substrate is produced by hydride vapor phase epitaxy. 
     
     
         5 . The method for producing at least one laser chip according to  claim 1 , wherein an absorber layer is applied to the substrate at least in places on the side edge. 
     
     
         6 . The method for producing at least one laser chip according to  claim 1 , wherein wet-chemical etching is carried out using an alkaline etching solution. 
     
     
         7 . The method for producing at least one laser chip according to  claim 1 , wherein the region of the side edge generated by the further plasma etching process extends at an angle of less than 85° to the main extension plane of the substrate. 
     
     
         8 . The method for producing at least one laser chip according to  claim 7 , wherein a mask remains on the semiconductor layer sequence after dry-chemical etching, and the mask protrudes beyond the semiconductor layer sequence, but not beyond the substrate. 
     
     
         9 . The method for producing at least one laser chip according to  claim 1 , wherein the substrate comprises a first region and a second region which are arranged one above the other along a vertical direction, wherein the vertical direction extends perpendicular to the main extension plane of the substrate and more material of the substrate is ablated, by dry-chemical etching, in the first region along a direction parallel to the main extension plane of the substrate than in the second region along a direction parallel to the main extension plane of the substrate. 
     
     
         10 . The method for producing at least one laser chip according to  claim 1 , wherein the substrate is completely cut along at least one direction perpendicular to the main extension plane of the substrate. 
     
     
         11 . The method for producing at least one laser chip according to  claim 10 , wherein the cutting step comprises sawing using a wedge-shaped saw blade. 
     
     
         12 . The method for producing at least one laser chip according to  claim 10 , wherein the cutting step comprises laser cutting. 
     
     
         13 . The method for producing at least one laser chip according to  claim 1 , wherein a plurality of side edges is formed by dry-chemical etching, wherein the side edges each extend, at least in places, transverse or perpendicular to the main extension plane of the substrate and the semiconductor layer sequence with the substrate is singulated along the side edges, forming a plurality of laser chips. 
     
     
         14 . A laser chip comprising:
 a semiconductor layer sequence having an active zone,   a substrate on which the semiconductor layer sequence is arranged, and   at least one side edge which extends, at least in places, transverse or perpendicular to the main extension plane of the substrate and which extends, at least in places, along the substrate and, at least in places, along the semiconductor layer sequence, wherein   the active zone is designed to emit laser radiation,   the side edge has at least one step, and   the side edge has a greater surface roughness along the substrate than along the semiconductor layer sequence, wherein   the side edge is formed by dry-chemical etching, the dry-chemical etching comprises a plasma etching process, and the dry-chemical etching comprises a further plasma etching process different from the plasma etching process.   
     
     
         15 . The laser chip according to  claim 14 , wherein the laser chip has a greater expansion in a plane which runs parallel to the main extension plane of the substrate and through the substrate than in a plane which runs parallel to the main extension plane of the substrate and through the semiconductor layer sequence. 
     
     
         16 . The laser chip according to  claim 14 , wherein the side edge has a further step. 
     
     
         17 . The laser chip according to  claim 14 , wherein an absorber layer is arranged on the substrate at the side edge. 
     
     
         18 . A laser chip comprising:
 a semiconductor layer sequence having an active zone,   a substrate on which the semiconductor layer sequence is arranged, and   at least one side edge which extends, at least in places, transverse or perpendicular to the main extension plane of the substrate and which extends, at least in places, along the substrate and, at least in places, along the semiconductor layer sequence, wherein   the active zone is designed to emit laser radiation,   the side edge has at least one step, and   the side edge has a greater surface roughness along the substrate than along the semiconductor layer sequence, wherein   an absorber layer is arranged on the substrate at the side edge.